Performance considerations
- Last Updated: July 30, 2025
- 5 minute read
- DataDirect Connectors
- ODBC
- Salesforce 8.0
- Documentation
Bulk Load Job Size (BulkLoadJobSize): This option can be used to improve performance by increasing the number of rows the driver loads at a time because fewer network round trips are required. However, a higher number of rows also causes the driver to consume more memory on the client.
- Load Balance Timeout (LoadBalanceTimeout): You can define how long to keep connections in the pool. The time that a connection was last used is compared to the current time and, if the timespan exceeds the value of the Load Balance Timeout option, the connection is destroyed. The Min Pool Size option can cause some connections to ignore this value.
- Connection Reset (ConnectionReset): Resetting a re-used connection to the initial configuration settings impacts performance negatively because the connection must issue additional commands to the server.
- Max Pool Size (MaxPoolSize): Setting the maximum number of connections that the pool can contain too low might cause delays while waiting for a connection to become available. Setting the number too high wastes resources.
- Min Pool Size (MinPoolSize): A connection pool is created when the first connection with a unique connection string connects to the database. The pool is populated with connections up to the minimum pool size, if one has been specified. The connection pool retains this number of connections, even when some connections exceed their Load Balance Timeout value.
If there is a TOP or LIMIT clause in the select query, the driver considers the TOP or LIMIT clause value as the expected number of rows in the result set and compares it with the value of the Bulk Fetch Threshold option to choose either Bulk API or REST API for executing the select query.
If the value of TOP or LIMIT clause is greater than that of the Bulk Fetch Threshold option, but the actual row count in the result set is less, the performance of the select query might be affected adversely.
Enable Bulk Load (EnableBulkLoad): The Enable Bulk Load option can be used to improve performance by enabling the driver to use the Salesforce Bulk API for inserts, updates, and deletes. Using the Salesforce Bulk API may significantly reduce the number of Web service calls used to execute a statement and, therefore, may improve performance. When Enable Bulk Load is set to 1 (enabled), the driver uses the Salesforce Bulk API based on the value of the Bulk Load Threshold connection option. If the number of affected rows exceeds the value of Bulk Load Threshold option, the driver uses the Salesforce Bulk API to execute the insert, update, or delete operation.
Fetch Size/Web Service Fetch Size (FetchSize/WSFetchSize): The connection options Fetch Size and Web Service Fetch Size can be used to adjust the trade-off between throughput and response time. In general, setting larger values for Web Service Fetch Size and Fetch Size will improve throughput, but can reduce response time.
For example, if an application attempts to fetch 100,000 rows from the remote data source and Web Service Fetch Size is set to 500, the driver must make 200 Web service calls to get the 100,000 rows. If, however, Web Service Fetch Size is set to 4000, the driver only needs to make 25 Web service calls to retrieve 100,000 rows. Web service calls are expensive, so generally, minimizing Web service calls increases throughput. In addition, many Cloud data sources impose limits on the number of Web service calls that can be made in a given period of time. Minimizing the number of Web service calls used to fetch data also can help prevent exceeding the data source call limits.
For many applications, throughput is the primary performance measure, but for interactive applications, such as Web applications, response time (how fast the first set of data is returned) is more important than throughput. For example, suppose that you have a Web application that displays data 50 rows to a page and that, on average, you view three or four pages. Response time can be improved by setting Fetch Size to 50 (the number of rows displayed on a page) and WSFetch Size to 200. With these settings, the driver fetches all of the rows from the remote data source that you would typically view in a single Web service call and only processes the rows needed to display the first page.